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Cummins/Onan KTA50 / KTTA50 Engine

The Cummins/Onan KTA50 / KTTA50 is a turbocharged engine. It powers generator sets from Cummins/Onan, including the DFM. It holds 169 L (44.6 gal) of oil and 348 L (91.9 gal) of coolant.

Also known as: Cummins KTA50 / KTTA50

Part of the Cummins/Onan KTA50 engine family — 16 variants share parts & fitment.

169.0 L

Oil capacity

On this pageSpecs Generator sets Maintenance FAQ Service intervals Torque & specs Fluids Fault codes Procedures Wiring

Engine specifications

Oil capacity	169.0 L
Coolant capacity	348.0 L
Aspiration	Turbocharged

Generator sets powered by this engine

Cummins/Onan DFM

How to read your Cummins/Onan engine serial & model number →

Common problems

Warning Status Indicator: This yellow lamp is lit whenever the control detects a warning condition.
Fix: After the condition is corrected, warning indicators can be reset by pressing the Reset switch. (It is not necessary to stop the generator set.) In auto mode, warning indicators can also be reset by cycling the remote reset input after the condition is corrected.
Warning lamp lights. 210
Fix: Indicates set is in standby mode but is not operating. Warning occurs when engine coolant temperature is 70 F (21 C) or lower. NOTE: In applications where the ambient temperature falls below 40F (4C), Low Engine Temp may be indicated even though the coolant heaters are operating. Indicates engine coolant heater is not operating or is not circulating coolant. Check for the following conditions: a. Coolant heater not connected to power supply. Check for blown fuse or disconnected heater cord and correct as required. b. Check for low coolant level and replenish if required. Look for possible coolant leakage points and repair as required. c. Contact an authorized service center if none of the above.
The FAULT 1 or FAULT 2 fault lamp lights. Engine shuts down immediately, or engine continues to run. FAULT 1 or FAULT 2
Fix: A. Fault lamp on. Correct fault and reset control. b. Poor battery cable connections. Clean the battery cable terminals and tighten all connections. c. Discharged or defective battery. Recharge or replace the battery.
Shutdown Status Indicator: This red lamp is lit whenever the control detects a shutdown condition.
Fix: After the condition is corrected, shutdown indicators can be reset by turning
Shutdown lamp lights. 200
Fix: Indicates engine oil pressure has dropped to an unacceptable level. If generator is powering critical loads and cannot be shut down, wait until next shutdown period then follow 201 Low Oil Pressure procedure. If engine can be stopped, follow 201 procedure. To check oil pressure, access Oil Pressure menu prior to clearing the fault.
PCC memory error. Data corruption of noncritical operating parameters. Warning lamp lights. 251
Fix: Contact an authorized service center.
PCC memory error. Data corruption of critical operating parameters. Shutdown lamp lights. 250
Fix: Contact an authorized service center.
OVERCRANK lamp lights and engine cannot be started
Fix: A. Check for empty fuel tank, fuel leaks, or plugged fuel lines and correct as required. d. Refer to Step 5.
Overcrank fault
Fix: Place Run/Stop/Remote switch in STOP position, depress Reset switch momentarily, wait two minutes for starter motor to cool and repeat starting procedure
One or more of the phase voltages has exceeded 130% of nominal, or has exceeded 110% of nominal for 10 seconds. Shutdown lamp lights. 301
Fix: Contact an authorized service center.
Non-Automatic lamp flashes.
Fix: Indicates Run/Off/Auto switch is not in the Auto position. This will prevent automatic starting if an automatic transfer switch is used. Move the Run/Off/Auto switch to the Auto position for automatic operation.
Indicates engine coolant level has fallen below the trip point. Shutdown lamp lights. 220
Fix: A. Check coolant level and replenish if low. Look for possible coolant leakage points and repair if necessary. b. Reset control and restart after locating and correcting problem. Contact an authorized service center.
Green RUN lamp lights following engine loads and cannot be shut down
Fix: A. Reduce load if possible by turning off non-critical loads. b. Check air inlets and outlets and remove any obstructions to airflow. c. Open doors or windows in generator area to increase ventilation. Allow engine to cool down completely before proceeding with the following checks: a. Check coolant level and replenish if low. Look for possible coolant leakage points and repair b. Check for obstructions to cooling airflow and correct as necessary. c. Check for a slipping fan belt and tighten if required. d. Reset control and restart after locating and correcting problem. Contact your Dealer or Distributor if none of the above.
Fuel supply is running low. Warning lamp lights. 241
Fix: Check fuel supply and replenish as required.
Engine will not crank. Shutdown lamp lights. 221
Fix: A. Poor battery cable connections. Clean the battery cable terminals and tighten all connections. b. Discharged or defective battery. Recharge or replace the battery. c. Contact an authorized service center for service of starter and starting system.

Compiled from service & troubleshooting documentation across every generator set that uses the Cummins/Onan KTA50 / KTTA50.

Maintenance schedule

Item	Spec	Capacity	Part #	Interval
Air filter	Clean with low pressure compressed air 30 psi/207 kPa, or soak 15 min in Donaldsons D1400 solvent		—
Fuel filter			—
Oil filter			—
Battery	Four, 12 Volt; Group 8D; CCA 1400 minimum; check electrolyte level at least every 200 hours		—	200 hr
Belt	Spring-loaded idler maintains correct belt tension		—
Coolant	Drain and replace mixture every year or after 500 hours	348.0 L	—	500 hr
Coolant filter			—
Oil	Refer to Cummins engine Operation and Maintenance Manual	169.0 L	—	250 hr

Pooled from every document that names this exact engine — confirm the interval and part number against your unit's serial number.

Service intervals

Item	Action	Hours	Months	Notes
crankcase oil	Change	50 hr		First service — Drain and replace the crankcase oil after the first 50 hours of operation on new generator sets (break-in)
Crankcase oil and filter	Change	250 hr	12 mo	Standby applications: change oil every 12 months or 250 hours, whichever comes first
Generator bearing (P7 only)	Lubricate	4500 hr		Re-lubrication period 4000-4500 hours; 75 grams Kluber ASONIC GHY72
Rupture basin leak detect switch	Test		12 mo	Check once a year; in some areas weekly inspections may be required by safety code regulations

Extracted from the manufacturer documentation linked to this model. Values are copied as printed; confirm against your unit's manual and serial number.

Service specifications

Type	Item	Value	Unit	Condition
Clearance	Air cleaner nozzle distance from element	at least 1 (25)	inch (mm)
Clearance	Angular alignment maximum T.I.R.	0.001	inch per inch of radius (center of shaft to indicator axis)	measuring deflection to bolt heads
Clearance	Float switch assembly float lift clearance below C-clip stop	1/8	inch (3 mm)	use a feeler gauge
Clearance	Generator-to-engine angular alignment (T.I.R.)	.001 in. per inch of radius (center of shaft to indicator axis), maximum	in	750 kW gensets and larger
Gap	MPU sensor to flywheel ring gear tooth	back it out one quarter turn	turn	sensor threaded in until it just touches gear tooth
Gap	Magnetic sensor air gap	.050- to .060-inch (1.27 to 1.52 mm)	inch (mm)
Other	AVR Droop setting	5	% at full load, 0 PF
Other	AVR voltage regulation (load regulation)	approximately ±0.5	% RMS
Other	Air cleaner element cleaning air pressure	30 (207)	psi (kPa)	low pressure compressed air through element from clean side
Other	Angular alignment maximum T.I.R.	.001 inches per inch of radius	in/in	center of shaft to indicator axis
Other	Battery electrolyte specific gravity	1.260		at 80°F
Other	Battery specific gravity (high ambient, above 95F/35C)	1.225		recommended to reduce electrolyte loss
Other	Battery specific gravity (recharge threshold)	below 1.260
Other	Battery specific gravity, fully charged	approximately 1.260	specific gravity	at 80 F (27 C)
Other	Continuous crank without cycle cranking option (PCC)	up to 75	seconds
Other	Cycle Cranker crank cycle time (A14-R4)	13- to 17-	seconds
Other	Cycle Cranker rest time (A14-R6)	8- to 12-	seconds
Other	Fuel lift height limit	6	feet	(1.8 meters) between fuel lift pump and bottom of dip tube
Other	GOV GAIN default value for paralleling applications	70	%
Other	Low oil pressure / high engine temperature fault time delay after starter disconnect	about 10	seconds
Other	Maximum cranking voltage drop	2	volts	difference between battery and starter terminals while cranking
Other	Output frequency adjustment range	+/- 5	%	set running, not in idle mode
Other	Over/Under Frequency Sensor Module - Over Hz Set, 50 Hz nominal	55	Hz	reset 53 Hz
Other	Over/Under Frequency Sensor Module - Over Hz Set, 60 Hz nominal	65	Hz	reset 63 Hz
Other	Over/Under Frequency Sensor Module - Under Hz Set, 50 Hz nominal	45	Hz	reset 47 Hz
Other	Over/Under Frequency Sensor Module - Under Hz Set, 60 Hz nominal	55	Hz	reset 57 Hz
Other	Over/Under Voltage Sensor Module time delay	typically 25 percent, approximately 2.5	seconds
Other	Overcrank cranking limit	75	seconds	three 15-second cranking cycles with two 15-second rest periods
Other	Overcrank cranking limit (standard control)	75	seconds
Other	Overcrank cycle cranking (Detector, standard)	three 15-second cranking cycles with two 15-second rest periods	seconds
Other	Overcrank cycle cranking (PCC)	3, 4, or 5 cycles; crank and rest times 7 to 20	seconds
Other	Overcrank cycling option	three 15-second cranking cycles with two 15-second rest periods		12-lamp control
Other	Overcrank limit (Detector, optional)	75	seconds
Other	REG VHZ (underfrequency roll-off) adjustable range	1 through 50; normal range 7 through 21
Other	Start delay (PCC, remote start in Auto)	0 to 300	seconds
Other	Start delay adjustment range	0 to 300	seconds
Other	Stop delay (PCC, remote stop in Auto)	0 to 600	seconds
Other	Stop delay adjustment range	0 to 600	seconds
Other	Time delay start (A15) adjustable	up to 15-	seconds
Other	Time delay stop (A15) adjustable	30-seconds to 5 minutes	minutes
Other	Under Frequency Roll Off (UFRO) knee point, 50 Hz units	48 to 49	Hz
Other	Under Frequency Roll Off (UFRO) knee point, 60 Hz units	58 to 59	Hz
Other	Under-frequency roll-off threshold (UFRO)	typically 59 Hz for 60 Hz applications and 49 Hz for 50 Hz applications	Hz	AVR UFRO pot preset
Pressure	Air cleaner element cleaning, compressed air pressure	30	psi (207 kPa)	blow through element from clean side; nozzle at least 1 inch (25 mm) away
Pressure	Detector oil pressure normal range after reset	25 to 40	psi (172 to 275 kPa)
Pressure	Engine oil pressure - K19 normal	50-70	psi (345-482 kPa)	run mode
Pressure	Engine oil pressure - K38 normal	45-65	psi (310-448 kPa)	run mode
Pressure	Engine oil pressure - K50 normal	50-70	psi (345-482 kPa)	run mode
Pressure	Engine oil pressure - L10/M11 normal	30-50	psi (207-345 kPa)	run mode
Pressure	Engine oil pressure - NTA 855 normal	35-50	psi (241-345 kPa)	run mode
Pressure	Engine oil pressure - V28 normal	50-90	psi (345-620 kPa)	run mode
Pressure	Engine oil pressure shutdown limit - L10/M11	20	psi (138 kPa)	run mode value
Pressure	Engine oil pressure shutdown limit - L10/M11	8	psi (55 kPa)	idle mode value
Pressure	Engine oil pressure warning limit - L10/M11	12	psi (83 kPa)	idle mode value
Pressure	Engine oil pressure warning limit - L10/M11	25	psi (172 kPa)	run mode value
Pressure	Idle oil pressure (PCC)	20	psi (138 kPa)	idle
Pressure	Idle oil pressure shutdown limit (PCC)	10	psi (69 kPa)	idle
Pressure	Idle oil pressure warning limit (PCC)	15	psi (103 kPa)	idle
Pressure	K19 engine idle oil pressure	20	psi (138 kPa)	idle
Pressure	K19 engine normal oil pressure	50-70	psi (345-482 kPa)	normal run

Extracted from the manufacturer documentation linked to this model. Values are copied as printed; confirm against your unit's manual and serial number.

Recommended fluids

Fluid	Grade	Standard	Ambient	Capacity	Notes
Coolant	soft water / E.G. / DCA mixture				Cooling system to be filled with soft water/E.G./DCA mixture (on-site review checklist).
Coolant	water/antifreeze mixture (permanent type antifreeze)	Clean, low mineral content water free of chloride, sulphate or acid			Mix water and antifreeze per supplier recommendation for lowest expected ambient temperature; do not use antifreeze containing anti-leak additives
Engine oil	SAE 5W synthetic	API class CC/CD; sulphated ash content not exceeding 1.85 percent; pour point 9°F (5°C) below lowest expected temperature; viscosity 10,000 mPa.s maximum at -31°F (-35°C) and 4.1 mm2/s minimum at 212°F (100°C)	above -25°C		Recommended when ambient temperature is consistently below -13°F (-25°C) and there is no provision to keep the engine warm; do not use petroleum base 5W grade oil
Engine oil	multigrade / multiviscosity	API Class CC/CD; maximum sulphated ash content 1.85 percent	-25°C to 35°C		Specifications section lists ambient ranges -13°F to 95°F (-25°C to 35°C), 14°F (-10°C) and above, and 32°F (0°C) and above; single grade oil not recommended; do not mix oils of another classification or brand
Fuel	Diesel				Day tank fuel transfer pump maintains reservoir of diesel fuel in the day tank.
Fuel	No. 2 diesel				Engine will also operate on No. 1 fuel or other similar fuels if they meet certain specifications
Grease	Kluber, type ASONIC GHY72			75.0 grams	P7 generator bearing re-lubrication grease fill quantity; fill period 4000-4500 hours. Must not be mixed with any other type.
Grease	Lithium based grease	Mobilux No. 2 or Shell Alvania R3		2.74 oz (81 ml)	Generator end bearing. Temperature range -22F to +248F (-30C to +120C). Grease should be equally divided between the bearing, bearing cap cavity, and bearing cartridge cavity.
Grease	Molykote	Onan #524-0118			Apply a layer on the end-bell bearing bore before inserting bearing
Grease	Lithium based grease, Mobilux No. 2 or Shell Alvania R3		-30°C to 120°C	2.74 oz (81 ml)	End bearing lubricant; grease equally divided between bearing, bearing cap cavity and bearing cartridge cavity.
Other	Donaldsons D1400 solvent (or equivalent)				Air cleaner element cleaning: soak filter at least 15 minutes in water and Donaldsons D1400 solvent.

Extracted from the manufacturer documentation linked to this model. Values are copied as printed; confirm against your unit's manual and serial number.

Fault codes

Code	Name	Meaning	Severity	Action
101	IDLE MODE	Indicates that the engine is operating in idle mode. Grounding the engine idle input causes generator build-up to be inhibited and the engine to be governed at 800 RPM.	Warning	Remove ground from engine idle input to return to normal speed and voltage.
102	EMERGENCY STOP	Local or remote Emergency Stop activated	Shutdown	Turn the switch clockwise and allow it to pop out (local only); move the Run/Off/Auto switch to Off; press the Reset switch; select Run or Auto as required. Can be reset only at the PCC front panel.
200	LOW OIL PRESSURE	Indicates engine oil pressure has dropped to an unacceptable level.	Warning	If generator is powering critical loads and cannot be shut down, wait until next shutdown period and then follow 201-SHUTDOWN procedure. Access the Oil Pressure menu prior to clearing the fault.
201	LOW OIL PRESSURE	Indicates engine oil pressure has dropped below the shutdown trip point.	Shutdown	Check oil level, replenish if low, reset control and restart; contact authorized service center.
204	OIL PRES SENDER	Indicates that the control has sensed that the engine oil pressure sender is out of its working range.	Warning	Check that the engine oil pressure sender is properly connected.
210	LOW COOLANT TEMP	Warning occurs when engine coolant temperature is 70°F (21°C) or lower.	Warning	Indicates engine coolant heater is not operating or is not circulating coolant. Check coolant heater power supply, low coolant level, and heater element current draw.
211	HIGH COOLANT TEMP	Indicates the engine coolant temperature is getting close to the recommended maximum temperature limit: 215° F (102° C) − standby or 207° F (97° C) − primary.	Warning	Review 212 correction list; increase in load or higher ambient may cause shutdown.
212	HIGH COOLANT TEMP	Indicates engine has overheated (coolant temperature has risen above the shutdown trip point: 215 F (102 C) - standby or 207 F (97 C) - primary).	Shutdown	Cool engine; check coolant level, airflow obstructions and fan belt; reset and restart.
213	COOLANT SENDER	Resistance of the coolant temperature sender is out of range.	Warning	Contact authorized service center.
214	LOW COOLANT LVL	Indicates engine coolant level has fallen below the trip point.	Warning	Cool engine; check coolant level and leaks; reset control and restart.
215	LOW COOLANT LVL	Indicates engine coolant level has fallen below the trip point.	Shutdown	Cool engine; check coolant level and leaks; reset control and restart. Shutdown will not occur in Idle mode.
220	MAG PICKUP	Mag pickup speed indication not sensed or does not match output frequency	Shutdown	Restart and check RPM; check PCC model setting; inspect and test MPU.
221	FAIL TO CRANK	Possible fault with control or starting system.	Shutdown	Clean and tighten battery cables; recharge or replace battery; contact service center.
222	OVERCRANK	Possible fuel system problem.	Shutdown	Check fuel tank, leaks, plugged lines, fuel filter and air filter; reset control and restart.
223	OVERSPEED	Indicates engine has exceeded normal operating speed. (115% ±1% of nominal).	Shutdown	Contact authorized service center.
224	FAIL TO SYNCHRONIZE	Generator set has not synchronized to the system bus within the allowable time frame.	Warning	Check governor system stability; adjust governing and synchronizer parameters; check fuel system.
226	FAIL TO CLOSE	Paralleling breaker has been given a signal to close, but has not closed properly.	Shutdown	Verify breaker charging mechanism; check close signal; verify auxiliary contact signals.
230	LOW DC VOLTAGE	Indicates battery voltage is below 10 VDC.	Warning	Recharge or replace the battery; check the battery charger fuse. Clean and tighten battery cable connections. Check engine DC alternator; replace if normal charging voltage is not obtained. Check float level if applicable.
231	HIGH DC VOLTAGE	Indicates battery voltage exceeds 32 VDC.	Warning	Lower battery charger float level if applicable; check engine DC alternator.
232	WEAK BATTERY	Indicates battery voltage drops below 60% of nominal for two seconds, during starting.	Warning	See warning message 230 LOW DC VOLTAGE.
240	LOW FUEL−DAY	Indicates day tank fuel supply is running low.	Warning	Check fuel supply and replenish as required.
241	LOW FUEL	Low fuel signal received.	Warning	Check fuel supply and replenish; check for short to ground in external wiring.
250	EEPROM ERROR	PCC memory error; data corruption of critical operating parameters.	Shutdown	Perform the initial start setup procedure; if the set shuts down on the same EEPROM ERROR message, replace the digital board (A32).
251	EEPROM ERROR	PCC memory error; data corruption of noncritical operating parameters.	Warning	Perform the adjustment procedures; if the same message occurs, perform calibration procedures; if the message persists, replace the digital board (A32).
252	EEPROM ERROR	PCC memory error; data corruption of noncritical operating parameters.	Warning	Verify values/choices selected and repeat the save operation; if the same message occurs, replace the digital board (A32).
260	CUSTOMER FAULT 1	When this customer defined input is closed to ground, the corresponding fault message is displayed. Programmable to initiate a shutdown or a warning.	Warning	Shutdown or warning preselected; message is editable; contact authorized service center.
261	GROUND FAULT	When a customer defined input is closed to ground, the corresponding fault message is displayed. Default message; editable for customer site requirements.	Warning	Shutdown or warning preselected; message is editable; contact authorized service center.
262	RUPTURE BASIN	When a customer defined input is closed to ground, the corresponding fault message is displayed. Default message; editable for customer site requirements.	Warning	Shutdown or warning preselected; message is editable; contact authorized service center.
263	HIGH GEN TEMP	When a customer defined input is closed to ground, the corresponding fault message is displayed. Default message; editable for customer site requirements.	Warning	Shutdown or warning preselected; message is editable; contact authorized service center.
270	PHASE ROTATION	The phase relationship between the generator set and the system bus is not matched.	Shutdown	Verify genset phase rotation matches bus; verify control wiring to bus PT module.
272	FIRST START	PowerCommand control is not receiving a proper signal from the system master first start sensor.	Warning	Verify Master First Start Sensor and interconnection wiring.
301	HIGH AC VOLTAGE	One or more phase voltages exceeded 130% of nominal, or exceeded 110% of nominal for 10 seconds.	Shutdown	Set display to GEN, VOLTS, L-N; determine if the output voltage the control sees is low or high; isolate PCC/alternator/excitation circuit.
303	LOW AC VOLTAGE	One or more phase voltages dropped below 85% of nominal for 10 seconds.	Shutdown	Contact authorized service center.
313	UNDER FREQUENCY	Indicates that engine speed has dropped below 90% of nominal for 10 seconds. Five seconds before shutdown, a Load Dump signal is initiated.	Shutdown	Load Dump signal initiated five seconds before shutdown; contact authorized service center.
320	OVERCURRENT	Indicates that generator output current has exceeded 110% of rated for 60 seconds.	Warning	Contact authorized service center.
321	OVERCURRENT	Indicates that generator output current has exceeded 110% of rated, and that a PCC time/current calculation has initiated an overcurrent shutdown.	Shutdown	Contact authorized service center.
322	SHORT CIRCUIT	Indicates that generator output current has exceeded 175% of rated.	Shutdown	Contact authorized service center.
330	OVERLOAD	Three-phase power output exceeds 105% of standby (or 115% of prime) rating.	Warning	Load Dump output activated after five seconds; warning activated after 60 seconds; contact authorized service center.
335	REVERSE POWER	Power is flowing into the generator set rather than out from the unit.	Shutdown	Verify CT connections, load sharing lines, and generator set frequency/voltage.
337	LOSS OF EXCITATION	Alternator excitation system is improperly adjusted or has failed.	Shutdown	Check output voltage calibration, load sharing lines, and leading power factor loads.
FAULT 1	Fault 1 (Red)	Undedicated customer-defined fault; may be programmed as timed or non-timed shutdown or fault light only.	Shutdown	Service as required by the customer-supplied fault indicating switches.
FAULT 2	Fault 2 (Red)	Undedicated customer-defined fault, same features as Fault 1.	Shutdown	Service as required by the customer-supplied fault indicating switches.
GF	Ground Fault Alarm (Optional)	Ground fault relay monitors neutral to ground connection and line to neutral, activating a fault alarm when the connection is broken or a ground fault is sensed.	Warning	Clear fault condition by pushing the Run/Stop (Reset)/Remote switch to Reset (auto reset link set at factory).
HET	High Engine Temperature (Red)	Engine shut down because of excessively high engine coolant temperature (greater than 230 deg F).	Shutdown	Check coolant level and leaks; service cooling system; reset engine control.
HI ENG TEMP	High Engine Temperature	Engine shut down due to critically high coolant temperature (above 215F/102C).	Shutdown
High Engine Temperature	High Engine Temperature	On a five-light system, the High Engine Temperature switch connects to module A13-20; closure applies a ground which turns on A13-Q6 triggering A13-CR7 to conduct, providing a ground path for the fault light and to relay A11-K2 for engine shutdown. On single-light systems it is connected in parallel with low oil pressure to pin 4 of A12	Shutdown	Check coolant level, radiator cooling duct, fan belts, temperature sensor, thermostat and city water input solenoid valve
LET	Low Engine Temperature (Yellow)	Engine temperature is less than 70 deg F and the engine might not start.	Warning	Plug in, repair or install engine coolant and oil heaters.
LO FUEL	Low Fuel	Fuel supply is marginally low, if equipped (Detector-12).	Warning
LO OIL PRES	Low Oil Pressure	Engine shut down due to critically low oil pressure (below 14 psi/97 kPa).	Shutdown
LOP	Low Oil Pressure (Red)	Engine shut down because of excessively low engine oil pressure (less than 14 psi).	Shutdown	Check oil level and oil leaks; service lubricating system; reset engine control.
LOW ENG TEMP	Low Engine Temperature	Engine water jacket temperature is 70F/21C or lower; indicates possible inoperative coolant heater (Detector-12).	Warning
LOW FUEL	Low Fuel (Yellow)	Fuel level in the supply tank has dropped below the reserve necessary to run the set at full load for the prescribed number of hours.	Warning	Fill the main fuel supply tank with the appropriate grade of fuel.
Low Engine Temperature	Low Engine Temperature	Closure of the Low Engine Temperature Sensing switch applies a ground to A13-8; A13-Q4 conducts and set-panel and remote Low Engine Temperature lights indicate a fault; there is no alarm or engine shutdown with this fault	Warning	Indicates a fault only; no shutdown or alarm
Low Oil Pressure	Low Oil Pressure	Closure of the low oil pressure switch applies a ground to pin 4 of the A12 module; A12-Q4 turns on causing unijunction A12-Q7 to fire and trigger A12-CR6; fault light illuminates and on standard installations alarm and engine shutdown are initiated (Penn State sets alarm only). An adjustable rheostat A12-R11 provides a timed-delay up to 10 seconds	Shutdown	Check oil level and oil pressure sensor; disconnect wire from TB11-30 and check if light remains on
OC	Overcrank (Red)	Engine shut down because it did not start during the timed cranking period (approximately 75 seconds, including two rest periods).	Shutdown	Service the set as necessary; reset engine control.
OS	Overspeed (Red)	Engine shut down because of overspeed.	Shutdown	Adjust the Electronic Overspeed Module; check governor for binding; reset engine control.
OVERCRANK	Overcrank	Starter locked out because of excessive cranking time (limited to 75 seconds).	Shutdown
OVERSPEED	Overspeed	Engine shut down because of excessive speed.	Shutdown
Overcrank	Overcrank	Engine fails to start after cranking for 75 seconds; capacitor A12-C1 on the Engine Monitor module charges to turn on A12-CR1, illuminates the fault light and applies a ground to pin 7 on A11 Engine Shutdown module which energizes A12-K1 allowing K12 to drop out and stop cranking	Shutdown	Check fuel system (valves open, tanks full) and ignition system; refer to engine manufacturer's troubleshooting
Overspeed	Overspeed	Engine speed in excess of 2010 rpm causes transistor A16-Q2 on the Overspeed Sensor module to conduct and apply a ground to pin 2 of A12 Engine Monitor module; A12-Q8 turns on and triggers A12-CR8 to illuminate the fault light and initiate shutdown and alarm	Shutdown	Check throttles for freedom of movement and governor linkage; check injector rack movement; verify governor setting
PRE HI ENG TEMP	Pre-High Engine Temperature	Coolant temperature is marginally high (205F/97C or higher).	Warning	Attend to when generator set is shut down.
PRE LO OIL PRES	Pre-Low Oil Pressure	Engine oil pressure is marginally low (20 psi/138 kPa or less).	Warning	Attend to when generator set is shut down.
PRE-HET	Pre High Engine Temperature (Yellow)	Engine coolant temperature is abnormally high (greater than 220 deg F).	Warning	Shut down if possible or disconnect non-critical loads; service cooling system.
PRE-LOP	Pre Low Oil Pressure (Yellow)	Engine oil pressure is abnormally low (less than 20 psi).	Warning	Shut down if possible or disconnect non-critical loads; service lubricating system.
RUN	Run (Green)	Green lamp comes on when both primary and secondary starter circuits open after unit starts.	Info
SWITCH OFF	Switch-off (Flashing Red)	The Run/Stop/Remote switch is in the Stop position, preventing remote automatic operation.	Info	Push the Run-Stop-Remote switch to Remote.

Extracted from the manufacturer documentation linked to this model. Values are copied as printed; confirm against your unit's manual and serial number.

Procedures

Aligning Generator with Engine (Angular Alignment) adjustment

⚠ Accidental starting of the generator set during this procedure presents the hazard of severe personal injury or death.

Tools: Dial indicator, Shims

Disconnect the negative (-) battery cable(s) before beginning.
Fasten a dial indicator to the generator shaft or cooling fan with the sensing point on the capscrew head or flat surface of the drive disc at the bolt circle diameter.
Bar the engine over in a clockwise rotation as viewed from engine flywheel; do not allow it to roll back on compression.
Determine the total indicator reading (T.I.R.) as the sum of the maximum positive and negative dial indicator readings over one revolution.
Measure the distance from the center of the generator shaft to the indicator measuring point.
Measure the distance from the generator side of the flex discs to the center of the generator mounting bolt.
Compare the distances; multiply this ratio times one half the T.I.R. to approximate the amount of shims to remove or add.

Angular Alignment Procedure adjustment

⚠ Accidental starting of the generator set during this procedure presents the hazard of severe personal injury or death. Make sure to disconnect the negative (-) battery cable(s) before beginning.

Tools: Dial indicator, Wooden shims

Disconnect the negative (-) battery cable(s) before beginning.
Fasten a dial indicator to the generator shaft or cooling fan with sensing point on capscrew head or flat surface of drive disc at bolt circle diameter.
Bar the engine over in a clockwise rotation as viewed from engine flywheel; do not allow it to roll back on compression.
Record maximum positive and negative dial indicator readings as the engine completes one revolution.
T.I.R. equals the sum of the maximum positive and negative readings.
Maximum T.I.R. should not be more than .001 inch for each inch of radius.
Remove equal shims from under both generator mounting feet to lower the generator.

Angular Alignment Procedure (Generator to Engine) adjustment

⚠ Accidental starting during this procedure presents the hazard of severe personal injury or death.

⚠ Do not bar engine over by prying on fan blade.

Tools: dial indicator

Disconnect the negative (-) battery cable(s) before beginning.
Fasten a dial indicator to the generator shaft or cooling fan with sensing point resting on the drive disc capscrew head/flat surface at the bolt circle diameter.
Bar the engine over in a clockwise rotation as viewed from the engine flywheel; do not allow it to roll back on compression at the end of travel of each reading.
Record the total indicator reading (T.I.R.) as the sum of the maximum positive and negative dial indicator readings over one engine revolution.
Compare the measured T.I.R. to the maximum allowed (.001 in. per inch of radius from center of shaft to indicator axis); add or remove shims under the generator mounting feet to correct.

Axial Alignment Procedure (Generator to Engine) adjustment

Tools: dial indicator

Fasten a dial indicator holding device to the skid base, engine block, or generator shell with the sensor point resting on the generator shaft hub.
Bar the engine over in a clockwise rotation through a couple of rotations, recording indicator readings at eight equally spaced points around the shaft diameter to obtain axial T.I.R.
Reduce the measured T.I.R. runout by one half if excessive vibration remains after angular alignment.

Gain Adjustment adjustment

Close the main line circuit breaker and apply approximately 1/4 of the rated load.
Make sure the engine speed is constant.
Turn the GAIN potentiometer clockwise slowly until the engine speed is not constant.
Slowly turn the potentiometer counterclockwise until a constant speed is achieved, then an additional 1/2 division.

Governed Speed Adjustment adjustment

For 60 Hz full load, set engine no-load governed speed to 60.0 Hz (1800 RPM) isochronous, 61.8 Hz (1854 RPM) for 3% droop, or 63.0 Hz (1890 RPM) for 5% droop.
For 50 Hz full load, set engine no-load governed speed to 50.0 Hz (1500 RPM) isochronous, 51.5 Hz (1545 RPM) for 3% droop, or 52.5 Hz (1575 RPM) for 5% droop.
Use the SPEED ADJUST potentiometer on the engine instrument panel for fine speed adjustments of less than ±100 RPM.

Governor Calibration Checks adjustment

Tools: Frequency meter or tachometer, Jumper wire

Start the generator set.
Adjust engine no-load speed to the desired allowable speed droop using the Run Speed potentiometer.
With no load, turn GAIN clockwise slowly until engine speed oscillates.
Reduce GAIN slowly counterclockwise until engine speed is stable.
Upset the governor by momentarily shorting terminals 7 and 10 on the governor control.
Apply and remove loads to check generator set response.

HC4-7 Axial Alignment Procedure adjustment

Tools: Dial indicator with magnetic base or clamp

Check only when an objectionable vibration is present.
Fasten dial indicator holding device to skid base, engine block, or generator shell with magnetic base or clamp.
Position sensor point on the generator shaft hub.
Bar the engine over in a clockwise rotation as viewed from engine flywheel through a couple of rotations.
Record indicator readings in eight equally spaced points around the shaft diameter.
Remove the capscrews connecting drive discs and flywheel and mark discs and flywheel.
Rotate engine or generator so drive disc holes are repositioned 180 degrees from original location.
Put capscrews back in and retorque. Recheck shaft alignment.
If runout unchanged, rotate discs to 30, 60 or 90 degrees from original location.
If T.I.R. does not improve, inspect flywheel pilot and drive disc runouts.

P7 Axial Alignment Procedure adjustment

Check only when an objectionable vibration is present.
Remove the capscrews connecting drive discs and flywheel.
Mark the drive discs and flywheel with respect to each other.
Rotate engine or generator so drive discs holes are repositioned two bolt holes from original location.
Put capscrews back in and retorque. Recheck/record vibration levels.
Repeat this test until drive disc holes are repositioned 180 degrees from original location.
Review vibration data and position drive disc in lowest recorded level location.

Preliminary Governor Adjustments adjustment

Idle Speed potentiometer: turn screw counterclockwise 20 turns then clockwise 10 turns to set mid position.
Run Speed potentiometer: turn screw counterclockwise 20 turns then clockwise 10 turns to set mid position.
Gain potentiometer: turn the screw fully counterclockwise.
Droop potentiometer: turn fully counterclockwise for isochronous operation; approximately 40 for 3 percent droop; approximately 80 for 5 percent droop.

Reconnection adjustment

Reconnect bus-bars for the different voltage per Figure 16
Reconnect lead from terminal 63 (inside control box) to either H3, H4 or H5
Select the proper tap on voltage reference transformer (T21) per Figure 2

Sensitivity Reference Circuit adjustment

Tools: Soldering iron

Solder wire W1 to terminal E1 for frequency sensitivity
Solder wire W1 to terminal E2 for non-frequency sensitivity

Extracted from the manufacturer documentation linked to this model. Values are copied as printed; confirm against your unit's manual and serial number.

Voltage reconnection

Voltage	Phase	Connection	Leads	Notes
		12 lead generator sets	Load wires are routed through the CTs	Reconnectable gensets (12 leads) have dual secondary CTs (3 pins); CT wire 2/3 to pin 2 (high voltage) or pin 3 (low voltage).
		6 lead generator sets	Generator output leads are routed through the CTs	Non-reconnectable gensets (6 leads) have single secondary CTs (2 pins).
		Cummins PowerCommand generic AC Reconnect Wiring Diagram 625-2755 (Rev. D) and 625-3100 (Rev. F)		Applies to models DFAA, DFAB, DFAC, DFBF, DFCB, DFCC, DFEB, DFEC, DFFB, DFGA, DFGB, DFJA, DFJB, DFJC, DFJD, DFLB, DFLC, DFLD, DFMB (625-2755) and models DFAA-DFMB plus DFCE, DFED, DQAA, DQAB, DQBA, DQBB (625-3100).
	A (U)	CT21	U load leads (A phase)	CT dot must face the generator; CT terminal 1 connects to metering circuit, terminal 2/3 to ground.
	B (V)	CT22	V load leads (B phase)	CT dot must face the generator; terminal 1 to metering circuit, terminal 2/3 to ground.
	C (W)	CT23	W load leads (C phase)	CT dot must face the generator; terminal 1 to metering circuit, terminal 2/3 to ground.
110/190	3	Code 517		50 Hz; transformer tap H3
115/200	3	Code 517		50 Hz; transformer tap H4
120/208	3	Code 17		60 Hz; transformer tap H3
120/208	3	Code 517		50 Hz; transformer tap H4
120/240	3	Code 5D		Not reconnectible; frequency 60 Hz; transformer tap H5
127/220	3	Code 17		60 Hz; transformer tap H4
127/220	3	Code 517		50 Hz; transformer tap H5
139/240	3	Code 17		60 Hz; transformer tap H5
220/380	3	Code 517 / Code 7		50 Hz H3 and 60 Hz H3; transformer tap H3
230/400	3	Code 517		50 Hz; transformer tap H4
240/416	3	Code 517 / Code 17		50 Hz H4 and 60 Hz H3; transformer tap H4
240/480	3	Code 6D		Not reconnectible; frequency 60 Hz; transformer tap H5
254/440	3	Code 517 / Code 17		50 Hz and 60 Hz; transformer tap H5
277/480	3	Code 17		60 Hz; transformer tap H5
347/600	3	Code 9X		60 Hz; transformer tap H5

Extracted from the manufacturer documentation linked to this model. Values are copied as printed; confirm against your unit's manual and serial number.

Parts cataloged across the Cummins/Onan KTA50 family

300

Part #	Description	Category
140-2096	Element, Primary (Outer)	Air filter
140-2098	Air Cleaner - Throwaway Type	Air filter
140-2467	Element, Safety (Inner)	Air filter
140-2501	Cleaner, Air (Disposable)	Air filter
140-2502	Band, Mounting – Air Cleaner	Air filter
140-2503	Bracket, Mounting	Air filter
140-3163	Cleaner, Air (No Replaceable Element)	Air filter
140-3230	Cleaner, Air (Includes Elements - See Ref. No. 25 and 26)	Air filter
309-0272	Regulator, Voltage - 24 VDC (Used on 35 A MP Alternator)	Alternator
309-0561	Alternator & Drive Components Group Pulley. Alternator - Multi Groove (Use with 35 A MP Alternator)	Alternator
503-1743-01	Alternator & Orive Components Group Pulley, Alternator - Multi Groove (Use with 35 AMP Alternator)	Alternator
206587	CAP, MAIN BEARING	Bearing cap
206588	CAP, MAIN BEARING	Bearing cap
98-5347	Decal - Caution Fan Drive & Lube Components Group Belt.	Belt
106069	SCREW, HEXAGON HEAD CAP	Bolt
205584	SCREW, TWELVE POINT CAP	Bolt
206028	SCREW, SOCKET HEAD CAP	Bolt
3032633	SCREW, TWELVE POINT CAP	Bolt
3177945	SCREW, HEX FLANGE HEAD CAP	Bolt
3628452	SCREW, HEXAGON HEAD CAP	Bolt
S-112	SCREW, HEXAGON HEAD CAP	Bolt
205684	BRACKET, LIFTING	Bracket lifting
205230	BUSSING	Bushing
0300-4623-29	DFLB (600V)	Current transformer
0300-4623-30	DFLC (600V)	Current transformer
0300-4623-52	DFLB BR (0-480V)	Current transformer
0300-4623-54	DFLC BR (0-480V)	Current transformer
3178803	CYLINDER BLOCK OPTION BP6089	Cylinder block
3178910	CYLINDER BLOCK	Cylinder block
148582	DOE, PIN	Dowel pin
70662	DOE, PIN	Dowel pin
3629497	DRAINCOCK	Draincock
206224	PLUG, EXPANSION	Expansion plug
206742	PLUG, EXPANSION	Expansion plug
3629168	PLUG, EXPANSION	Expansion plug
122-0757	Filter. Water - W/Corosion Inhibiting Chemical	Filter
159-1445	Reservoir, Fuel	Fluid
FS1216	Fuel/Water Sep Spin-On	Fuel filter
121-0113	Gasket, Pump	Gasket
121-0117	Gasket, Hand Hole	Gasket
205059	WASHER, PLAIN	Gasket
3002993	DOE, RING	Gasket
3025485	WASHER, PLAIN	Gasket
3176857	DOE, RING	Gasket
3178450	WASHER, PLAIN	Gasket
3178457	WASHER, PLAIN	Gasket
M-4352581	Upper Gasket Set	Gasket
S-604	WASHER, LOCK	Gasket
S-610	WASHER, LOCK	Gasket
338-2529	Harness. Wiring	Harness
128-0108	Insulation, Hose – Bulk (Order By The Foot – 12 Feet Required)	Hose
130-3538	Chemical DCA4 Service Pre-Charging Complete System	Hose
130-3576	Clamp, Hose	Hose
130-5588-02	Tube, Water Heater	Hose
130-5589-02	Tube, Water Heater	Hose
130-5590-02	Tube, Water Heater	Hose
130-5591-02	Tube, Water Heater	Hose
338-2925	Hose, Radiator	Hose
501-0704	Line, Flexible Fuel - Fuel Out	Hose
501-0707	Line, Flexible Fuel - Fuel In	Hose
502-1162	Connector, Hose (3/8")	Hose
503-0183	Clamp, Hose	Hose
503-0685	Clamp, Hose	Hose
503-0868	Clamp, Hose - T-Bolt Type (3.5" NON)	Hose
503-1140	Hose, Rubber	Hose
503-1484	Elbow, Hose (45 Deg) (7" ID)	Hose
503-1620	Hose – Bulk (3/8" ID) (Order by the Foot)	Hose
503-1727	Hose, Radiator (3” ID x 10”)	Hose
503-1728	Hose (3” ID x 5–1/2”)	Hose
503-1870-11	Clamp, Hose	Hose
503-1870-12	Clamp, Hose	Hose
505-0324	Hose. Bulk (Sold by the Foot) Two Feet Required Nipple, Pipe - Half (3/4 NPT x 2"LG)	Hose
518-0548-24	Clamp, Hose	Hose
98-5759	Drive - Multi Groove Hose, Flexible - Lube (Grease)	Hose
98-5842	Clamp, Hose - T-Bolt Type (3.5" NON)	Hose
3375004	Dial Indicator Kit for injector and valve adjustment	Injector
3822575	Injector and valve adjustment kit	Injector
3011884	INSERT, LINER	Insert liner
3019150	INSERT, LINER	Insert liner
3021148	INSERT, LINER	Insert liner
206580	BEARING, MAIN	Main bearing
206581	BEARING, MAIN A/R No.2,3,4,5,6,7,&8, Upper	Main bearing
206582	BEARING, MAIN A/R No.2,3,4,5,6,7,&8, Upper	Main bearing
206583	BEARING, MAIN A/R No.2,3,4,5,6,7,&8, Upper	Main bearing
206584	BEARING, MAIN A/R No.2,3,4,5,6,7,&8, Upper	Main bearing
206590	BEARING, MAIN	Main bearing
206591	BEARING, MAIN A/R No.2,3,4,5,6,7,&8, Lower	Main bearing
206592	BEARING, MAIN A/R No.2,3,4,5,6,7,&8, Lower	Main bearing
206593	BEARING, MAIN A/R No.2,3,4,5,6,7,&8, Lower	Main bearing
206594	BEARING, MAIN A/R No.2,3,4,5,6,7,&8, Lower	Main bearing
206600	BEARING, MAIN	Main bearing
206601	BEARING, MAIN A/R No.1&9, Upper	Main bearing
206602	BEARING, MAIN A/R No.1&9, Upper	Main bearing
206603	BEARING, MAIN A/R No.1&9, Upper	Main bearing
206604	BEARING, MAIN A/R No.1&9, Upper	Main bearing
206610	BEARING, MAIN	Main bearing
206611	BEARING, MAIN A/R No.1&9, Lower	Main bearing
206612	BEARING, MAIN A/R No.1&9, Lower	Main bearing
206613	BEARING, MAIN A/R No.1&9, Lower	Main bearing
206614	BEARING, MAIN A/R No.1&9, Lower	Main bearing
3018210	SET, MAIN BEARING STANDARD	Main bearing set
3018211	SET, MAIN BEARING A/R .010 Inch O/S	Main bearing set
3018212	SET, MAIN BEARING A/R .020 Inch O/S	Main bearing set
3018213	SET, MAIN BEARING A/R .030 Inch O/S	Main bearing set
LF3325	Full-flow spin-on lubricating oil filter element	Oil filter
016-40820	Harness, Wiring (Includes Cable Ties and Terminals)	Service part / kit
102-1335	Plug, Oil Drain	Service part / kit
121-0116	Cover, Hydraulic Hole	Service part / kit
130-2981	Cap. Radiator - 7#PSI	Service part / kit
130-3758	Radiator (includes Cap)	Service part / kit
140-1260	Fitting, Safety Filter	Service part / kit
140-1548	Indicator, Service	Service part / kit
140-2097	Cleaner, Air (Includes Elements)	Service part / kit
140-2099	Band	Service part / kit
140-2395	Tube, Air Inlet	Service part / kit
140-2504-01	Bracket - Right Side	Service part / kit
140-2504-02	Bracket - Left Side	Service part / kit
140-2508	Tube, Air Inlet (7" x 9" - 3/4")	Service part / kit
140-2509	Tube, Air Inlet	Service part / kit
140-2515	Bracket, Mounting	Service part / kit
140-2519	Tube, Air Inlet	Service part / kit
140-2521	Tube, Air Inlet	Service part / kit
140-2528	Shield – Air In Heat	Service part / kit
300-2856	Board Assy, Printed Circuit	Service part / kit
300-2863	Board Assy, Printed Circuit - Relay Assembly- (A14)	Service part / kit
3007525	(3022157) KIT, LINER LINER, CYLINDER	Service part / kit
301-9054-01	Decal - Panel Front Markings (Control With Meters)	Service part / kit
301-9054-02	Clip - Fastener	Service part / kit
301-9054-03	Clip - Fastener	Service part / kit
3012611	CYLINDER LINER (O/S) KIT, LINER A/R .020 inch O/S	Service part / kit
3012612	CYLINDER LINER (O/S) KIT, LINER A/R .030 Inch O/S	Service part / kit
302-1720	Meter, Frequency (M23)	Service part / kit
302-1753	Ammeter (M22) See Current Transformer & Ammeter Installation Figure for Parts)	Service part / kit
302-1800	Ammeter (M22) Scale in Amps as Indicated 0-2000/0-4000 (600 VAC Application) 0-3000/0-6000 (120-480 VAC Application)	Service part / kit
302-1908	Screw. Cap - Hex Head (M8-1.25 x 35MM)	Service part / kit
305-0813-01	Battery charger, Onan, 120V, 375W	Service part / kit
305-0818-02	EOOO-21002	Service part / kit
307-1056	Relay. 24 VDC	Service part / kit
307-1987	2 307-1056 3 3 815-0388 6 4 323-0804 3 5 815-0544 3 6 319-0447 1 7 NOTE 1 REF 8 NOTE 2	Service part / kit
308-0882	Decal - Panel Front Markings (Control Without Meters)	Service part / kit
309-0436	Decal - Model Identification ONAN GEN SET CUMMINS GEN SET CUMMINS ONAN GEN SET	Service part / kit
309-0437	(222"F)	Service part / kit
309-0635-02	Valve, Check	Service part / kit
3096680	Piston STC 13.8:1 Ratio	Service part / kit
3096681	Piston KT Series 15.5:1 Ratio	Service part / kit
3096682	Piston KTA Series 14.5:1 Ratio	Service part / kit
3096683	Piston 13.5:1 Ratio	Service part / kit
3096684	Piston KTA 15.7:1 Ratio	Service part / kit
3096685	Piston STC 13.9:1 Ratio	Service part / kit
319-0447	Screw. Machine - Pan Head. Cross-Recessed Drive (#6-32 x 1/2")	Service part / kit
319-0754	Tie. Cable	Service part / kit
322-0363	Component 322-0363	Service part / kit
323-0804	Screw. Machine - Round Head with IT Lock Washer (#6-32 x 1/2")	Service part / kit
323-1200	# Socket, Contact (Used in J1, J2)	Service part / kit
323-1304	tiotming, Umector	Service part / kit
323-1306	Genset component (SJB series)	Service part / kit
3318201	Battery Cable Group	Service part / kit
332-0052	Clamp, Loop	Service part / kit
332-0607	Block, Terminal (T81)	Service part / kit
332-1279	Terminal. Lug - Ring (3/8	Service part / kit
332-1292	Terminal Board (Includes Parts Marked #)	Service part / kit
332-1445	Tie, Cable 18 98-5219 1 Decal - Panel Front (Not I l l u s t r a t e d ) 19 98-5220 1 Decal	Service part / kit
332-1673	Terminal, Wire - Spade	Service part / kit
332-2634	Clamp, Hose	Service part / kit
332-2723	Strip. Marker	Service part / kit
333-0677-01	Heater, Coolant - 4990 Watt	Service part / kit
333-0677-02	Heater, Coolant - 6420 Watt	Service part / kit
3375005	Dial indicator extension	Service part / kit
3375007	Support Plate / Support Block for dial indicator	Service part / kit
338-1835	Harness, Wiring (A13 to A l l )	Service part / kit
338-1836	Harness, Wiring (A14 to All) (Relays)	Service part / kit
338-1904	Harness. Wiring (A15 to All)	Service part / kit
338-2278	Harness. Wiring - AC (Includes Terminal Block & Cable Ties) [Used only with meters]	Service part / kit
338-2532	Terminal. Lug - Forked (No. 6 Screw)	Service part / kit
355-0093	Voltmeter (M21) Dual Scale 0-300/0-600V Single Scale 0-750V	Service part / kit
3628731	Piston STC Kit	Service part / kit
3630913	Piston KTA-50-G7	Service part / kit
3631241	Piston Kit STC 13.9:1 Ratio	Service part / kit
3631242	Piston Kit 13.5:1 Ratio	Service part / kit
3631243	Piston Kit KTA 15.7:1 Ratio	Service part / kit
3631244	Piston Kit KTA Series 14.5:1 Ratio	Service part / kit
3631245	Piston Kit KT Series 15.5:1 Ratio	Service part / kit
3631246	Piston Kit STC 13.8:1 Ratio	Service part / kit
3801268	CYLINDER LINER (O/S) KIT, LINER A/R .040 Inch O/S	Service part / kit
3803530	Piston Assembly STC	Service part / kit
3804747	Piston Kit KTA-50-G7	Service part / kit
3804885	Piston KTA-50-G8/G9	Service part / kit
406-0333	Component 406-0333	Service part / kit
406-0334	Clip, Retaining - Turnbutton Fastener	Service part / kit
4089847	Piston Kit GTA38/19	Service part / kit
4090013	Piston Kit KTA-38-M2	Service part / kit
4090029	Piston Kit QSK19CE	Service part / kit
4090181	Piston GTA38/19	Service part / kit
4097889	Piston KTA-38-M2	Service part / kit
4910463	Piston QSK19R/M	Service part / kit
4910465	Piston QSK Series	Service part / kit
4916177	Piston GTA/GQSK19	Service part / kit
4918058	Piston QSK19CE	Service part / kit
4922319	Piston QSK19C	Service part / kit
4955233	Piston Kit QSK19R/M	Service part / kit
4955235	Piston Kit QSK Series	Service part / kit
4955236	Piston Kit QSK19C	Service part / kit
4955238	Piston Kit GTA/GQSK19	Service part / kit
501-0520	Screw, Cap - Hex Head (3/8-24 x 5/8")	Service part / kit
501-0524	Washer, Lock - EIT (3/8")	Service part / kit
501-0558	Line. Flexible - Bypass	Service part / kit
503-1717	Elbow, Reducer (45 Deg) (7" ID to 6" ID)	Service part / kit
503-1720	Insert, Reducer (6" OD to 5-1/2" ID)	Service part / kit
503-1730	503-0183 21 503-1731 22 505-0324 23 504-0171 24 505-0102 25 505-0132 26 505-0102 27 28 29	Service part / kit
504-0028	Valve, Radiator Drain	Service part / kit
505-0007	Belt. Drive - Multi Groove (Used with 35 A MP Alternator * Pulley, Alternator - Multi Groove (Use with 75 A MP Alternator)	Service part / kit
505-0017	Bushing, Pipe – Reducer (3/8" to 1/4")	Service part / kit
505-0021	Bushing, Pipe - Reducer (3/4º to 1/2º)	Service part / kit
505-0100	Nipple, Pipe - Close (1/2”)	Service part / kit
505-0102	Filter. Water - W/Corosion Inhibiting	Service part / kit
505-0117	Bushing, Reducer - Flush, Brass (1/2' NPT x3/8° NPT)	Service part / kit
505-0132	Nipple, Pipe - Close (3/4 NPT x l-3/8"LG) Elbow. Pipe - 90* (3/4 NPT)	Service part / kit
505-0376	Elbow – 45 Deg (3/8")	Service part / kit
508-0015	Washer, Insulating - Fiber (#8)	Service part / kit
511-0161-02	.*	Service part / kit
517-0131	Capacitor (Used across Voltmeter Terminals on some Sets)	Service part / kit
518-0548-42	Clamp, Retainer 4 Prior To December 1996 Production (Mounted On Top And Side Of Control Box Wrapper)	Service part / kit
526-0030	Washer, Flat (3/8")	Service part / kit
800-0055	Screw, Cap – Hex Head (3/8–16 x 2-1/4")	Service part / kit
800-0062	Nut, Insulated	Service part / kit
800-0094	Screw, Cap – Hex Head (1/2–13 x 2")	Service part / kit
800-0270	DCA4 Service Pre-Charging Complete System	Service part / kit
800-2060	Screw, Cap - Hex Head (M8x 1.25 x35)	Service part / kit
809-0035	Screw, Machine - Thread Cutting, Round Head (#8 X 3/4')	Service part / kit
812-0063	853-0003 300-2856 338-1836 812-0063 853-0003 300-2863 338-1835 332-1445 NOTE 1 NOTE 2 332	Service part / kit
812-0065	Screw, Machine - Round Head (#6 - 32 x 5/8')	Service part / kit
812-0084	Screw. Machine - Round Head (	Service part / kit
815-0388	Bracket. Mounting - Relay Lead(s), Electrical Wire, Electrical - 20 AW G, Insulated Terminal, Wire - Forked, 18-20 Gauge	Service part / kit
815-0544	Screw, Machine - Round Head IT Washer (#6 - 32 x 1/2')	Service part / kit
821-0004	Screw, Self-Locking - Hex	Service part / kit
821-0029	Screw, Self–Locking – Hex Washer Head (3/8–16 x 3/4")	Service part / kit
821-0033	Screw, Self–Locking – Hex Washer Head (7/16–14 x 3/4")	Service part / kit
821-5004-03	Screw, Self-Locking – Hex Washer Head (3/8–16 x 1")	Service part / kit
850-0050	Washer, Lock - Spring (3/8”)	Service part / kit
853-0003	Washer, Lock - ET (#6)	Service part / kit
856-0008	Washer, Lock - EIT (5/16'1)	Service part / kit
856-0010	Washer, Lock - EIT (3/8')	Service part / kit
870-0131	Nut. Hex - with ET (#10-32)	Service part / kit
870-0196	Nut, Insulating (#8)	Service part / kit
870-0281	Nut, Self-Locking – Hex Washer Head (3/8–16)	Service part / kit
900-0181	PCC Control Service Manual	Service part / kit
903-0128	NA	Service part / kit
903-0208	NA	Service part / kit
903-0608	NA	Service part / kit
98-4732	Caution	Service part / kit
98-4798	Decal - Caution "7# PSI HOT WATER SYSTEM"	Service part / kit
98-5298	Decal - Panel Rear Markings (All Control Panels)	Service part / kit
98-5299	Decal - Panel Rear Markings (All Control Panels)	Service part / kit
98-5316	Decal - Panel Rear Markings (All Control Panels)	Service part / kit
98-5387	Nut, Self-Locking - with ET Lockwasher (#10-32)	Service part / kit
98-5393	Screw, Tapping - Round Head (#8 x 3/4")	Service part / kit
98-5822	Bushing, Reducer - Flush (1/2 NPT x 3/8 NPT)	Service part / kit
98-6108-03	Decal - Model Identification	Service part / kit
98-6111-03	ONAN GEN SET CUMMINS GEN SET	Service part / kit
98-6139-03	CUMMINS ONAN GEN SET	Service part / kit
98-6169	Terminal Assembly (Includes Replaceable Items 26 thru 29)	Service part / kit
F-2375	A single line drawing of the prime power system	Service part / kit
M-3804747	Piston Kit	Service part / kit
68445	PIN, GROOVE	Pin
3628605	PLUG, PIPE	Pipe plug
3628607	PLUG, PIPE	Pipe plug
3178464	PLATE, COVER	Plate cover
121-0111	Drive, Pump	Pump
159-1451	Pump, Fuel Transfer	Pump
3011076	SEAL, D RING	Seal
3014668	SEAL, D RING	Seal
3081489	SEAL, OIL	Seal
3177556	SEAL, RECTANGULAR RING	Seal
508-0292	Washer, Sealing - Copper	Seal
509-0283-01	Seal	Seal
509-0336	Seal, O-Ring	Seal
509-0337	Seal, O-Ring	Seal
193-0244	Sender, Pressure - 0i1	Sensor
193-0375	# Sender, Water Temperature	Sensor
309-0269	Sender, Temperature-Lo Engine	Sensor
960-0181	Service manual	Service manual
960-0302	Service manual	Service manual
960-0504	PCC Control Service Manual	Service manual
960-0507	Detector Control Service Manual	Service manual
3033853	SHAFT, IDLER	Shaft idler
3175281	SHAFT, IDLER	Shaft idler
205741	SHIM, A/R .007 Inch O/S	Shim
205742	SHIM, A/R .008 Inch O/S	Shim
205743	SHIM, A/R .009 Inch O/S	Shim
205744	SHIM, A/R .020 Inch O/S	Shim
205745	SHIM, A/R .031 Inch O/S	Shim
149-2232	Starter - 24 VDC	Starter
3000138	SUPPORT, BEARING	Support bearing
309-0649	Thermostat (Includes Connector Socket) (S11)	Thermostat
3000139	BEARING, THRUST	Thrust bearing
3001708	BEARING, THRUST A/R .010 Inch O/S	Thrust bearing
3001709	BEARING, THRUST A/R .020 Inch O/S	Thrust bearing
3001710	BEARING, THRUST A/R .030 Inch O/S	Thrust bearing
3001711	BEARING, THRUST A/R .040 Inch O/S	Thrust bearing
3179664	VALVE, PISTON COOLING	Valve piston cooling

Parts cataloged across all variants of this engine family — verify the exact part fits your specific variant and serial number before ordering.

Common questions

What is the oil capacity of the Cummins/Onan KTA50 / KTTA50?

The Cummins/Onan KTA50 / KTTA50 engine has an oil capacity of 169.0 liters.

Which generators use the Cummins/Onan KTA50 / KTTA50 engine?

The Cummins/Onan KTA50 / KTTA50 powers 1 generator set(s), including Cummins/Onan DFM.

How often should you change the oil in the Cummins/Onan KTA50 / KTTA50?

The Cummins/Onan KTA50 / KTTA50 oil change interval is every 250 hours.

What is a common problem with the Cummins/Onan KTA50 / KTTA50 engine?

A commonly reported issue on generators using the Cummins/Onan KTA50 / KTTA50 is: Warning Status Indicator: This yellow lamp is lit whenever the control detects a warning condition.. Fix: After the condition is corrected, warning indicators can be reset by pressing the Reset switch. (It is not necessary to stop the generator set.) In auto mode, warning indicators can also be reset by cycling the remote reset input after the condition is corrected..